Support for newer debian\ubuntu sandboxes, build and packaging updates

Fakeroot helper utility support updated, examples updated

Packaging updates, examples reworked

Fixes:

• Minor fixes at example-configs
• Packaging and build fixes

Example configs:

• Example configs that use external debian\ubuntu root-fs was reworked. Such configs now using "debian-sandbox.cfg.lua" config file as base, and contain only additions relative to base config.
• Added support for upcoming ubuntu-18.04 distro.

Packages:

• Packages for Ubuntu: https://launchpad.net/~dark-caster/+archive/ubuntu/sandboxer
• Packages for openSUSE, Debian and Ubuntu: https://build.opensuse.org/repositories/home:Warhammer40k:sandboxer

Minor fixes and additions

Fixes:

• Fix sandboxer-desktop-file-creator when launched via relative symlink

Additions:

• Added proper bwrap startup failure detection, no need to wait for startup timeout

deb packages:

• Packages for Debian and Ubuntu: https://build.opensuse.org/repositories/home:Warhammer40k:sandboxer
• Packages for Ubuntu: https://launchpad.net/~dark-caster/+archive/ubuntu/sandboxer

Major update

• Added sandboxer-download-extra.sh helper script - download precompiled binaries for use with external root-fs based on various distros
• Added Debian and Ubuntu packaging
• Packages for Debian and Ubuntu: https://build.opensuse.org/repositories/home:Warhammer40k:sandboxer
• Packages for Ubuntu: https://launchpad.net/~dark-caster/+archive/ubuntu/sandboxer
• Added sandbox' session control scripts to perform termination\kill of all processes running in selected sandbox
• Added sandboxer.service for systemd - gracefully terminate all running sandboxes on system shutdown
• Various updates for example sandbox-configs, and example scripts

Install-scripts fixes, minor example-configs updates and fixes

Build script fix: remove Fakeroot-UserNS external directory if clonin…

…g or configuration was failed

Minor fixes and new example configs

v0.2

sandboxer: dropbox example config file updated

First release

v0.1

README.md updated

External precompiled binaries. Not for direct use!

This is an external binaries, precompiled for various platforms. For use in case of troubles when using default binaries compiled with the project. All stuff posted here downloaded by sandboxer-download-extra.sh script, and not intended for direct use.